Is it possible to return more complex data types like:
{width:myWidth, height:myHeight} from a javascript to a calling (.net) client?

...to be able to read out named properties in the result of a SOAP call.

It does not raise any errors, but there seems to be no real result data at all - just the intormation about a data type. Is it possible, or do you have to build and return an xml-string of your own.

"Arrays of arrays" returns the correct data, but the arrays are not separated from each other, but seem to transform into one data structure when returned, and you would have to parse the data returned by knowing the number of dimensions.

That is
Array(myFilesInfoArray, myFontsInfoArray)
is returned as if it was one array - all data intact, but the two arrays are so to say "merged" in the result.